The singular fibre of the Hitchin map
arXiv:1012.5541 · doi:10.1093/imrn/rns020
Abstract
Given any line bundle L of positive degree, on a compact Riemann surface, let be the moduli space of L-twisted Higgs pairs of rank 2 with fixed determinant isomorphic to and traceless Higgs field. We give a description of the singular fibre of the Hitchin map , when the corresponding spectral curve has any singularity of type . In particular, we prove directly that this fibre is connected.
28 pages; v3; minor changes: added Proposition 3.7 and main Theorem 8.1 now also refers the fibre over zero; final version